On 2021-03-18 15:09, Fujii Masao wrote:
Thanks for your comments!
On 2021/03/17 22:24, torikoshia wrote:
I remade the patch and introduced a function
pg_print_backend_memory_contexts(PID) which prints the memory contexts
of
the specified PID to elog.
Thanks for the patch!
=# SELECT pg_print_backend_memory_contexts(450855);
** log output **
2021-03-17 15:21:01.942 JST [450855] LOG: Printing memory contexts
of PID 450855
2021-03-17 15:21:01.942 JST [450855] LOG: level: 0
TopMemoryContext: 68720 total in 5 blocks; 16312 free (15 chunks);
52408 used
2021-03-17 15:21:01.942 JST [450855] LOG: level: 1 Prepared
Queries: 65536 total in 4 blocks; 35088 free (14 chunks); 30448 used
2021-03-17 15:21:01.942 JST [450855] LOG: level: 1 pgstat
TabStatusArray lookup hash table: 8192 total in 1 blocks; 1408 free (0
chunks); 6784 used
..(snip)..
2021-03-17 15:21:01.942 JST [450855] LOG: level: 2
CachedPlanSource: 4096 total in 3 blocks; 680 free (0 chunks); 3416
used: PREPARE hoge_200 AS SELECT * FROM pgbench_accounts WHERE aid =
1111111111111111111111111111111111111...
2021-03-17 15:21:01.942 JST [450855] LOG: level: 3
CachedPlanQuery: 4096 total in 3 blocks; 464 free (0 chunks); 3632
used
..(snip)..
2021-03-17 15:21:01.945 JST [450855] LOG: level: 1 Timezones:
104128 total in 2 blocks; 2584 free (0 chunks); 101544 used
2021-03-17 15:21:01.945 JST [450855] LOG: level: 1 ErrorContext:
8192 total in 1 blocks; 7928 free (5 chunks); 264 used
2021-03-17 15:21:01.945 JST [450855] LOG: Grand total: 2802080
bytes in 1399 blocks; 480568 free (178 chunks); 2321512 used
As above, the output is almost the same as MemoryContextStatsPrint()
except for the way of expression of the level.
MemoryContextStatsPrint() uses indents, but
pg_print_backend_memory_contexts() writes it as "level: %d".
This format looks better to me.
Since there was discussion about enlarging StringInfo may cause
errors on OOM[1], this patch calls elog for each context.
As with MemoryContextStatsPrint(), each context shows 100
children at most.
I once thought it should be configurable, but something like
pg_print_backend_memory_contexts(PID, num_children) needs to send
the 'num_children' from requestor to dumper and it seems to require
another infrastructure.
Creating a new GUC for this seems overkill.
If MemoryContextStatsPrint(), i.e. showing 100 children at most is
enough, this hard limit may be acceptable.
Can't this number be passed via shared memory?
The attached patch uses static shared memory to pass the number.
As documented, the current implementation allows that when multiple
pg_print_backend_memory_contexts() called in succession or
simultaneously, max_children can be the one of another
pg_print_backend_memory_contexts().
I had tried to avoid this by adding some state information and using
before_shmem_exit() in case of process termination for cleaning up the
state information as in the patch I presented earlier, but since kill()
returns success before the dumper called signal handler, it seemed
there were times when we couldn't clean up the state.
Since this happens only when multiple pg_print_backend_memory_contexts()
are called and their specified number of children are different, and the
effect is just the not intended number of children to print, it might be
acceptable.
Or it might be better to wait for some seconds if num_chilren on shared
memory is not the initialized value(meaning some other process is
requesting to print memory contexts).
Only superusers can call pg_print_backend_memory_contexts().
+ /* Only allow superusers to signal superuser-owned backends. */
+ if (superuser_arg(proc->roleId) && !superuser())
The patch seems to allow even non-superuser to request to print the
memory
contexts if the target backend is owned by non-superuser. Is this
intentional?
I think that only superuser should be allowed to execute
pg_print_backend_memory_contexts() whoever owns the target backend.
Because that function can cause lots of log messages.
Thanks, it's not intentional, modified it.
I'm going to add documentation and regression tests.
Added them.
Regards,
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index 9492a3c6b9..e834b923e4 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -24781,6 +24781,33 @@ SELECT collation for ('foo' COLLATE "de_DE");
</para></entry>
</row>
+ <row>
+ <entry role="func_table_entry"><para role="func_signature">
+ <indexterm>
+ <primary>pg_print_backend_memory_contexts</primary>
+ </indexterm>
+ <function>pg_print_backend_memory_contexts</function> (
+ <parameter>pid</parameter> <type>integer</type>,
+ <parameter>max_children</parameter> <type>integer</type> )
+ <returnvalue>boolean</returnvalue>
+ </para>
+ <para>
+ Prints the memory contexts whose backend process has the specified
+ process ID.
+ <parameter>max_children</parameter> limits the max number of children
+ to print per one parent context.
+ Note that when multiple
+ <function>pg_print_backend_memory_contexts</function> called in
+ succession or simultaneously, <parameter>max_children</parameter> can
+ be the one of another
+ <function>pg_print_backend_memory_contexts</function>.
+ Backtrace will be printed based on the log configuration set. See
+ <xref linkend="runtime-config-logging"/> for more information.
+ Only superusers can call this function even when the specified process
+ is non-superuser backend.
+ </para></entry>
+ </row>
+
<row>
<entry role="func_table_entry"><para role="func_signature">
<indexterm>
diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c
index 3e4ec53a97..785374719f 100644
--- a/src/backend/storage/ipc/ipci.c
+++ b/src/backend/storage/ipc/ipci.c
@@ -46,6 +46,7 @@
#include "storage/sinvaladt.h"
#include "storage/spin.h"
#include "utils/snapmgr.h"
+#include "utils/memutils.h"
/* GUCs */
int shared_memory_type = DEFAULT_SHARED_MEMORY_TYPE;
@@ -269,6 +270,7 @@ CreateSharedMemoryAndSemaphores(void)
BTreeShmemInit();
SyncScanShmemInit();
AsyncShmemInit();
+ McxtPrintShmemInit();
#ifdef EXEC_BACKEND
diff --git a/src/backend/storage/ipc/procsignal.c b/src/backend/storage/ipc/procsignal.c
index c6a8d4611e..dabb2025b1 100644
--- a/src/backend/storage/ipc/procsignal.c
+++ b/src/backend/storage/ipc/procsignal.c
@@ -30,6 +30,7 @@
#include "storage/shmem.h"
#include "storage/sinval.h"
#include "tcop/tcopprot.h"
+#include "utils/memutils.h"
/*
* The SIGUSR1 signal is multiplexed to support signaling multiple event
@@ -440,6 +441,20 @@ HandleProcSignalBarrierInterrupt(void)
/* latch will be set by procsignal_sigusr1_handler */
}
+/*
+ * HandleProcSignalPrintMemoryContext
+ *
+ * Handle receipt of an interrupt indicating print memory context.
+ * Signal handler portion of interrupt handling.
+ */
+static void
+HandleProcSignalPrintMemoryContext(void)
+{
+ InterruptPending = true;
+ PrintMemoryContextPending = true;
+ /* latch will be set by procsignal_sigusr1_handler */
+}
+
/*
* Perform global barrier related interrupt checking.
*
@@ -580,6 +595,29 @@ ProcessProcSignalBarrier(void)
ConditionVariableBroadcast(&MyProcSignalSlot->pss_barrierCV);
}
+/*
+ * ProcessPrintMemoryContextInterrupt
+ * The portion of print memory context interrupt handling that runs
+ * outside of the signal handler.
+ */
+void
+ProcessPrintMemoryContextInterrupt(void)
+{
+ int max_children;
+
+ PrintMemoryContextPending = false;
+
+ LWLockAcquire(McxtPrintLock, LW_SHARED);
+ max_children = *MaxChildrenPerContext;
+ LWLockRelease(McxtPrintLock);
+
+ ereport(LOG,
+ (errmsg("Printing memory contexts of PID %d. Max number of children per context is %d", MyProcPid, max_children)));
+
+ MemoryContextStatsDetail(TopMemoryContext, max_children, false);
+}
+
+
/*
* If it turns out that we couldn't absorb one or more barrier types, either
* because the barrier-processing functions returned false or due to an error,
@@ -675,6 +713,9 @@ procsignal_sigusr1_handler(SIGNAL_ARGS)
if (CheckProcSignal(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN))
RecoveryConflictInterrupt(PROCSIG_RECOVERY_CONFLICT_BUFFERPIN);
+ if (CheckProcSignal(PROCSIG_PRINT_MEMORY_CONTEXT))
+ HandleProcSignalPrintMemoryContext();
+
SetLatch(MyLatch);
errno = save_errno;
diff --git a/src/backend/storage/lmgr/lwlocknames.txt b/src/backend/storage/lmgr/lwlocknames.txt
index 6c7cf6c295..f2aa1852b1 100644
--- a/src/backend/storage/lmgr/lwlocknames.txt
+++ b/src/backend/storage/lmgr/lwlocknames.txt
@@ -53,3 +53,4 @@ XactTruncationLock 44
# 45 was XactTruncationLock until removal of BackendRandomLock
WrapLimitsVacuumLock 46
NotifyQueueTailLock 47
+McxtPrintLock 48
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index 2b1b68109f..6fe47d1229 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3295,6 +3295,9 @@ ProcessInterrupts(void)
if (ParallelMessagePending)
HandleParallelMessages();
+
+ if (PrintMemoryContextPending)
+ ProcessPrintMemoryContextInterrupt();
}
diff --git a/src/backend/utils/adt/mcxtfuncs.c b/src/backend/utils/adt/mcxtfuncs.c
index c02fa47550..07a95dd115 100644
--- a/src/backend/utils/adt/mcxtfuncs.c
+++ b/src/backend/utils/adt/mcxtfuncs.c
@@ -61,7 +61,7 @@ PutMemoryContextsStatsTupleStore(Tuplestorestate *tupstore,
/* Examine the context itself */
memset(&stat, 0, sizeof(stat));
- (*context->methods->stats) (context, NULL, (void *) &level, &stat);
+ (*context->methods->stats) (context, NULL, (void *) &level, &stat, true);
memset(values, 0, sizeof(values));
memset(nulls, 0, sizeof(nulls));
diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 73e0a672ae..32fe971386 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -34,6 +34,7 @@ volatile sig_atomic_t ClientConnectionLost = false;
volatile sig_atomic_t IdleInTransactionSessionTimeoutPending = false;
volatile sig_atomic_t IdleSessionTimeoutPending = false;
volatile sig_atomic_t ProcSignalBarrierPending = false;
+volatile sig_atomic_t PrintMemoryContextPending = false;
volatile uint32 InterruptHoldoffCount = 0;
volatile uint32 QueryCancelHoldoffCount = 0;
volatile uint32 CritSectionCount = 0;
diff --git a/src/backend/utils/mmgr/aset.c b/src/backend/utils/mmgr/aset.c
index ec6c130d0f..8e7fe09a0f 100644
--- a/src/backend/utils/mmgr/aset.c
+++ b/src/backend/utils/mmgr/aset.c
@@ -272,7 +272,8 @@ static Size AllocSetGetChunkSpace(MemoryContext context, void *pointer);
static bool AllocSetIsEmpty(MemoryContext context);
static void AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
static void AllocSetCheck(MemoryContext context);
@@ -1336,11 +1337,12 @@ AllocSetIsEmpty(MemoryContext context)
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
+ * is_dst_stderr: is the output should be stderr or elog.
*/
static void
AllocSetStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals, bool is_dst_stderr)
{
AllocSet set = (AllocSet) context;
Size nblocks = 0;
@@ -1379,7 +1381,7 @@ AllocSetStats(MemoryContext context,
"%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
- printfunc(context, passthru, stats_string);
+ printfunc(context, passthru, stats_string, is_dst_stderr);
}
if (totals)
diff --git a/src/backend/utils/mmgr/generation.c b/src/backend/utils/mmgr/generation.c
index 2b90034764..b286308aa4 100644
--- a/src/backend/utils/mmgr/generation.c
+++ b/src/backend/utils/mmgr/generation.c
@@ -155,7 +155,8 @@ static Size GenerationGetChunkSpace(MemoryContext context, void *pointer);
static bool GenerationIsEmpty(MemoryContext context);
static void GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
static void GenerationCheck(MemoryContext context);
@@ -665,6 +666,7 @@ GenerationIsEmpty(MemoryContext context)
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
+ * is_dst_stderr: is the output should be stderr or elog.
*
* XXX freespace only accounts for empty space at the end of the block, not
* space of freed chunks (which is unknown).
@@ -672,7 +674,7 @@ GenerationIsEmpty(MemoryContext context)
static void
GenerationStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals, bool is_dst_stderr)
{
GenerationContext *set = (GenerationContext *) context;
Size nblocks = 0;
@@ -704,7 +706,7 @@ GenerationStats(MemoryContext context,
"%zu total in %zd blocks (%zd chunks); %zu free (%zd chunks); %zu used",
totalspace, nblocks, nchunks, freespace,
nfreechunks, totalspace - freespace);
- printfunc(context, passthru, stats_string);
+ printfunc(context, passthru, stats_string, is_dst_stderr);
}
if (totals)
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 84472b9158..5389cf4507 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -23,6 +23,10 @@
#include "mb/pg_wchar.h"
#include "miscadmin.h"
+#include "storage/proc.h"
+#include "storage/procarray.h"
+#include "storage/procsignal.h"
+#include "utils/fmgrprotos.h"
#include "utils/memdebug.h"
#include "utils/memutils.h"
@@ -37,6 +41,12 @@
*/
MemoryContext CurrentMemoryContext = NULL;
+/*
+ * MaxChildrenPerContext
+ * Max number of children to print per one parent context.
+ */
+int *MaxChildrenPerContext = NULL;
+
/*
* Standard top-level contexts. For a description of the purpose of each
* of these contexts, refer to src/backend/utils/mmgr/README
@@ -55,9 +65,11 @@ MemoryContext PortalContext = NULL;
static void MemoryContextCallResetCallbacks(MemoryContext context);
static void MemoryContextStatsInternal(MemoryContext context, int level,
bool print, int max_children,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
static void MemoryContextStatsPrint(MemoryContext context, void *passthru,
- const char *stats_string);
+ const char *stats_string,
+ bool is_dst_stderr);
/*
* You should not do memory allocations within a critical section, because
@@ -487,6 +499,89 @@ MemoryContextMemAllocated(MemoryContext context, bool recurse)
return total;
}
+/*
+ * McxtPrintShmemInit
+ * Initialize shared memory area
+ */
+void
+McxtPrintShmemInit(void)
+{
+ bool found;
+
+ MaxChildrenPerContext = (int *)
+ ShmemInitStruct("Max number of children per context",
+ sizeof(int),
+ &found);
+ if (!found)
+ {
+ *MaxChildrenPerContext = 0;
+ }
+}
+
+/*
+ * pg_print_backend_memory_contexts
+ * Print memory contexts of the specified backend process.
+ */
+Datum
+pg_print_backend_memory_contexts(PG_FUNCTION_ARGS)
+{
+ int pid = PG_GETARG_INT32(0);
+ int max_children = PG_GETARG_INT32(1);
+
+ PGPROC *proc = BackendPidGetProc(pid);
+
+ if(max_children <= 0)
+ {
+ ereport(WARNING,
+ (errmsg("%d is invalid value", max_children),
+ errhint("second parameter is the number of context and it must be set to a value greater than or equal to 1")));
+
+ PG_RETURN_BOOL(false);
+ }
+
+ /*
+ * Check whether the target process is PostgreSQL backend process.
+ */
+ if (proc == NULL)
+ {
+ /*
+ * According to the thread below, it might be better to
+ * change this message.
+ *
+ * https://www.postgresql.org/message-id/CALj2ACW7Rr-R7mBcBQiXWPp%3DJV5chajjTdudLiF5YcpW-BmHhg%40mail.gmail.com
+ *
+ * Until the conclusion of the discussion, output the same
+ * message as pg_cancel_backend().
+ */
+ ereport(WARNING,
+ (errmsg("PID %d is not a PostgreSQL server process", pid)));
+
+ PG_RETURN_BOOL(false);
+ }
+
+ /* Only allow superusers to print memory contexts. */
+ if (!superuser())
+ {
+ ereport(WARNING,
+ (errmsg("must be a superuser to print memory contexts")));
+ PG_RETURN_BOOL(false);
+ }
+
+ LWLockAcquire(McxtPrintLock, LW_EXCLUSIVE);
+ *MaxChildrenPerContext = max_children;
+ LWLockRelease(McxtPrintLock);
+
+ if(!SendProcSignal(pid, PROCSIG_PRINT_MEMORY_CONTEXT, InvalidBackendId))
+ PG_RETURN_BOOL(true);
+ else
+ {
+ ereport(WARNING,
+ (errmsg("failed to send signal: %m")));
+
+ PG_RETURN_BOOL(false);
+ }
+}
+
/*
* MemoryContextStats
* Print statistics about the named context and all its descendants.
@@ -499,7 +594,7 @@ void
MemoryContextStats(MemoryContext context)
{
/* A hard-wired limit on the number of children is usually good enough */
- MemoryContextStatsDetail(context, 100);
+ MemoryContextStatsDetail(context, 100, true);
}
/*
@@ -508,19 +603,28 @@ MemoryContextStats(MemoryContext context)
* Entry point for use if you want to vary the number of child contexts shown.
*/
void
-MemoryContextStatsDetail(MemoryContext context, int max_children)
+MemoryContextStatsDetail(MemoryContext context, int max_children, bool is_dst_stderr)
{
MemoryContextCounters grand_totals;
memset(&grand_totals, 0, sizeof(grand_totals));
- MemoryContextStatsInternal(context, 0, true, max_children, &grand_totals);
+ MemoryContextStatsInternal(context, 0, true, max_children, &grand_totals, is_dst_stderr);
- fprintf(stderr,
- "Grand total: %zu bytes in %zd blocks; %zu free (%zd chunks); %zu used\n",
- grand_totals.totalspace, grand_totals.nblocks,
- grand_totals.freespace, grand_totals.freechunks,
- grand_totals.totalspace - grand_totals.freespace);
+ if (is_dst_stderr)
+ fprintf(stderr,
+ "Grand total: %zu bytes in %zd blocks; %zu free (%zd chunks); %zu used\n",
+ grand_totals.totalspace, grand_totals.nblocks,
+ grand_totals.freespace, grand_totals.freechunks,
+ grand_totals.totalspace - grand_totals.freespace);
+ else
+ ereport(LOG_SERVER_ONLY,
+ (errhidestmt(true),
+ errhidecontext(true),
+ errmsg_internal("Grand total: %zu bytes in %zd blocks; %zu free (%zd chunks); %zu used",
+ grand_totals.totalspace, grand_totals.nblocks,
+ grand_totals.freespace, grand_totals.freechunks,
+ grand_totals.totalspace - grand_totals.freespace)));
}
/*
@@ -533,7 +637,8 @@ MemoryContextStatsDetail(MemoryContext context, int max_children)
static void
MemoryContextStatsInternal(MemoryContext context, int level,
bool print, int max_children,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals,
+ bool is_dst_stderr)
{
MemoryContextCounters local_totals;
MemoryContext child;
@@ -545,7 +650,7 @@ MemoryContextStatsInternal(MemoryContext context, int level,
context->methods->stats(context,
print ? MemoryContextStatsPrint : NULL,
(void *) &level,
- totals);
+ totals, is_dst_stderr);
/*
* Examine children. If there are more than max_children of them, we do
@@ -560,11 +665,13 @@ MemoryContextStatsInternal(MemoryContext context, int level,
if (ichild < max_children)
MemoryContextStatsInternal(child, level + 1,
print, max_children,
- totals);
+ totals,
+ is_dst_stderr);
else
MemoryContextStatsInternal(child, level + 1,
false, max_children,
- &local_totals);
+ &local_totals,
+ is_dst_stderr);
}
/* Deal with excess children */
@@ -574,16 +681,31 @@ MemoryContextStatsInternal(MemoryContext context, int level,
{
int i;
- for (i = 0; i <= level; i++)
- fprintf(stderr, " ");
- fprintf(stderr,
- "%d more child contexts containing %zu total in %zd blocks; %zu free (%zd chunks); %zu used\n",
- ichild - max_children,
- local_totals.totalspace,
- local_totals.nblocks,
- local_totals.freespace,
- local_totals.freechunks,
- local_totals.totalspace - local_totals.freespace);
+ if (is_dst_stderr)
+ {
+ for (i = 0; i <= level; i++)
+ fprintf(stderr, " ");
+ fprintf(stderr,
+ "%d more child contexts containing %zu total in %zd blocks; %zu free (%zd chunks); %zu used\n",
+ ichild - max_children,
+ local_totals.totalspace,
+ local_totals.nblocks,
+ local_totals.freespace,
+ local_totals.freechunks,
+ local_totals.totalspace - local_totals.freespace);
+ }
+ else
+ ereport(LOG_SERVER_ONLY,
+ (errhidestmt(true),
+ errhidecontext(true),
+ errmsg_internal("level: %d %d more child contexts containing %zu total in %zd blocks; %zu free (%zd chunks); %zu used",
+ level,
+ ichild - max_children,
+ local_totals.totalspace,
+ local_totals.nblocks,
+ local_totals.freespace,
+ local_totals.freechunks,
+ local_totals.totalspace - local_totals.freespace)));
}
if (totals)
@@ -605,12 +727,14 @@ MemoryContextStatsInternal(MemoryContext context, int level,
*/
static void
MemoryContextStatsPrint(MemoryContext context, void *passthru,
- const char *stats_string)
+ const char *stats_string,
+ bool is_dst_stderr)
{
int level = *(int *) passthru;
const char *name = context->name;
const char *ident = context->ident;
int i;
+ char truncated_ident[110];
/*
* It seems preferable to label dynahash contexts with just the hash table
@@ -623,11 +747,11 @@ MemoryContextStatsPrint(MemoryContext context, void *passthru,
ident = NULL;
}
- for (i = 0; i < level; i++)
- fprintf(stderr, " ");
- fprintf(stderr, "%s: %s", name, stats_string);
+ truncated_ident[0] = '\0';
+
if (ident)
{
+ char delimiter[] = ": ";
/*
* Some contexts may have very long identifiers (e.g., SQL queries).
* Arbitrarily truncate at 100 bytes, but be careful not to break
@@ -637,24 +761,42 @@ MemoryContextStatsPrint(MemoryContext context, void *passthru,
int idlen = strlen(ident);
bool truncated = false;
+ strcat(truncated_ident, delimiter);
+
if (idlen > 100)
{
idlen = pg_mbcliplen(ident, idlen, 100);
truncated = true;
}
- fprintf(stderr, ": ");
+
+ i = strlen(delimiter);
+
while (idlen-- > 0)
{
unsigned char c = *ident++;
if (c < ' ')
c = ' ';
- fputc(c, stderr);
+ truncated_ident[i++] = c;
}
+ truncated_ident[i] = '\0';
+
if (truncated)
- fprintf(stderr, "...");
+ strcat(truncated_ident, "...");
+ }
+
+ if (is_dst_stderr)
+ {
+ for (i = 0; i < level; i++)
+ fprintf(stderr, " ");
+ fprintf(stderr, "%s: %s%s\n", name, stats_string, truncated_ident);
}
- fputc('\n', stderr);
+ else
+ ereport(LOG_SERVER_ONLY,
+ (errhidestmt(true),
+ errhidecontext(true),
+ errmsg_internal("level: %d %s: %s%s",
+ level, name, stats_string, truncated_ident)));
}
/*
diff --git a/src/backend/utils/mmgr/slab.c b/src/backend/utils/mmgr/slab.c
index 9213be7c95..479b08bedd 100644
--- a/src/backend/utils/mmgr/slab.c
+++ b/src/backend/utils/mmgr/slab.c
@@ -135,7 +135,8 @@ static Size SlabGetChunkSpace(MemoryContext context, void *pointer);
static bool SlabIsEmpty(MemoryContext context);
static void SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
static void SlabCheck(MemoryContext context);
#endif
@@ -632,11 +633,13 @@ SlabIsEmpty(MemoryContext context)
* printfunc: if not NULL, pass a human-readable stats string to this.
* passthru: pass this pointer through to printfunc.
* totals: if not NULL, add stats about this context into *totals.
+ * is_dst_stderr: is the output should be stderr or elog.
*/
static void
SlabStats(MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals)
+ MemoryContextCounters *totals,
+ bool is_dst_stderr)
{
SlabContext *slab = castNode(SlabContext, context);
Size nblocks = 0;
@@ -671,7 +674,7 @@ SlabStats(MemoryContext context,
"%zu total in %zd blocks; %zu free (%zd chunks); %zu used",
totalspace, nblocks, freespace, freechunks,
totalspace - freespace);
- printfunc(context, passthru, stats_string);
+ printfunc(context, passthru, stats_string, is_dst_stderr);
}
if (totals)
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 93393fcfd4..ff6a9d2186 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -7917,6 +7917,12 @@
proargnames => '{name, ident, parent, level, total_bytes, total_nblocks, free_bytes, free_chunks, used_bytes}',
prosrc => 'pg_get_backend_memory_contexts' },
+# print memory context of specified backend
+{ oid => '4543', descr => 'print memory contexts of specified backend',
+ proname => 'pg_print_backend_memory_contexts',
+ provolatile => 'v', prorettype => 'bool',
+ proargtypes => 'int4 int4', prosrc => 'pg_print_backend_memory_contexts' },
+
# non-persistent series generator
{ oid => '1066', descr => 'non-persistent series generator',
proname => 'generate_series', prorows => '1000',
diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h
index 013850ac28..711d6c2089 100644
--- a/src/include/miscadmin.h
+++ b/src/include/miscadmin.h
@@ -84,6 +84,7 @@ extern PGDLLIMPORT volatile sig_atomic_t ProcDiePending;
extern PGDLLIMPORT volatile sig_atomic_t IdleInTransactionSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t IdleSessionTimeoutPending;
extern PGDLLIMPORT volatile sig_atomic_t ProcSignalBarrierPending;
+extern PGDLLIMPORT volatile sig_atomic_t PrintMemoryContextPending;
extern PGDLLIMPORT volatile sig_atomic_t ClientConnectionLost;
diff --git a/src/include/nodes/memnodes.h b/src/include/nodes/memnodes.h
index 9331ef80fd..87a8501c37 100644
--- a/src/include/nodes/memnodes.h
+++ b/src/include/nodes/memnodes.h
@@ -52,7 +52,8 @@ typedef struct MemoryContextCounters
*/
typedef void (*MemoryStatsPrintFunc) (MemoryContext context, void *passthru,
- const char *stats_string);
+ const char *stats_string,
+ bool is_dst_stderr);
typedef struct MemoryContextMethods
{
@@ -66,7 +67,8 @@ typedef struct MemoryContextMethods
bool (*is_empty) (MemoryContext context);
void (*stats) (MemoryContext context,
MemoryStatsPrintFunc printfunc, void *passthru,
- MemoryContextCounters *totals);
+ MemoryContextCounters *totals,
+ bool is_dst_stderr);
#ifdef MEMORY_CONTEXT_CHECKING
void (*check) (MemoryContext context);
#endif
diff --git a/src/include/storage/procsignal.h b/src/include/storage/procsignal.h
index 4ae7dc33b8..0bfe290477 100644
--- a/src/include/storage/procsignal.h
+++ b/src/include/storage/procsignal.h
@@ -34,6 +34,8 @@ typedef enum
PROCSIG_PARALLEL_MESSAGE, /* message from cooperating parallel backend */
PROCSIG_WALSND_INIT_STOPPING, /* ask walsenders to prepare for shutdown */
PROCSIG_BARRIER, /* global barrier interrupt */
+ PROCSIG_PRINT_MEMORY_CONTEXT, /* ask specified backend to print the
+ memory context */
/* Recovery conflict reasons */
PROCSIG_RECOVERY_CONFLICT_DATABASE,
@@ -69,6 +71,7 @@ extern int SendProcSignal(pid_t pid, ProcSignalReason reason,
extern uint64 EmitProcSignalBarrier(ProcSignalBarrierType type);
extern void WaitForProcSignalBarrier(uint64 generation);
extern void ProcessProcSignalBarrier(void);
+extern void ProcessPrintMemoryContextInterrupt(void);
extern void procsignal_sigusr1_handler(SIGNAL_ARGS);
diff --git a/src/include/utils/memutils.h b/src/include/utils/memutils.h
index 36aae4e51c..db638c2f3f 100644
--- a/src/include/utils/memutils.h
+++ b/src/include/utils/memutils.h
@@ -63,6 +63,9 @@ extern PGDLLIMPORT MemoryContext CurTransactionContext;
/* This is a transient link to the active portal's memory context: */
extern PGDLLIMPORT MemoryContext PortalContext;
+
+extern int *MaxChildrenPerContext;
+
/* Backwards compatibility macro */
#define MemoryContextResetAndDeleteChildren(ctx) MemoryContextReset(ctx)
@@ -84,9 +87,11 @@ extern MemoryContext MemoryContextGetParent(MemoryContext context);
extern bool MemoryContextIsEmpty(MemoryContext context);
extern Size MemoryContextMemAllocated(MemoryContext context, bool recurse);
extern void MemoryContextStats(MemoryContext context);
-extern void MemoryContextStatsDetail(MemoryContext context, int max_children);
+extern void MemoryContextStatsDetail(MemoryContext context, int max_children,
+ bool is_dst_stderr);
extern void MemoryContextAllowInCriticalSection(MemoryContext context,
bool allow);
+extern void McxtPrintShmemInit(void);
#ifdef MEMORY_CONTEXT_CHECKING
extern void MemoryContextCheck(MemoryContext context);
diff --git a/src/test/modules/test_misc/t/002_print_memory_context_validation.pl b/src/test/modules/test_misc/t/002_print_memory_context_validation.pl
new file mode 100644
index 0000000000..61e318806f
--- /dev/null
+++ b/src/test/modules/test_misc/t/002_print_memory_context_validation.pl
@@ -0,0 +1,89 @@
+use strict;
+use warnings;
+use PostgresNode;
+use TestLib;
+use Test::More tests => 4;
+
+# Set up node with logging collector
+my $node = get_new_node('primary');
+$node->init();
+$node->append_conf(
+ 'postgresql.conf', qq{
+ logging_collector = on
+ lc_messages = 'C'
+ });
+
+$node->start();
+
+# Verify that log output gets to the file
+$node->psql('postgres', 'select pg_print_backend_memory_contexts(pg_backend_pid(), 100)');
+
+# might need to retry if logging collector process is slow...
+my $max_attempts = 180 * 10;
+
+my $current_logfiles;
+for (my $attempts = 0; $attempts < $max_attempts; $attempts++)
+{
+ eval {
+ $current_logfiles = slurp_file($node->data_dir . '/current_logfiles');
+ };
+ last unless $@;
+ usleep(100_000);
+}
+die $@ if $@;
+
+note "current_logfiles = $current_logfiles";
+
+like(
+ $current_logfiles,
+ qr|^stderr log/postgresql-.*log$|,
+ 'current_logfiles is sane');
+
+my $lfname = $current_logfiles;
+$lfname =~ s/^stderr //;
+chomp $lfname;
+
+my $logfile;
+my $print_count;
+
+# Verify that the backtraces of the processes are logged into logfile.
+for (my $attempts = 0; $attempts < $max_attempts; $attempts++)
+{
+ $logfile = $node->data_dir . '/' . $lfname;
+ chomp $logfile;
+ print "file is $logfile";
+ open my $fh, '<', $logfile
+ or die "Could not open '$logfile' $!";
+ while (my $line = <$fh>)
+ {
+ chomp $line;
+ if ($line =~ m/Grand total: \d+ bytes in \d+ blocks/)
+ {
+ $print_count++;
+ }
+ }
+ last if $print_count == 1;
+ usleep(100_000);
+}
+
+is($print_count, 1, 'found expected memory context print in the log file');
+
+my $output;
+
+$node->psql('postgres', 'select pg_print_backend_memory_contexts(pg_backend_pid(), 0)',
+ stderr => \$output);
+
+like(
+ $output,
+ qr/0 is invalid value/,
+ 'max_children must be set to a value greater than or equal to 1');
+
+$node->psql('postgres', 'select pg_print_backend_memory_contexts(1, 10)',
+ stderr => \$output);
+
+like(
+ $output,
+ qr/PID 1 is not a PostgreSQL server process/,
+ 'target PID is not PostgreSQL server process');
+
+$node->stop('fast');
